DE69721309T9 - REDUCING THE FORMATION OF CAVITIES IN HARDENABLE ADHESIVE COMPOSITIONS - Google Patents

Abstract

In accordance with the present invention, adhesive formulations have been developed which enable curing of adhesively bonded assemblies (i.e., assemblies which comprise devices which have been adhesively bonded to substrates) with dramatically reduced occurrence of void formation upon curing. In many instances, void formation can be eliminated employing invention compositions. In accordance with another aspect of the present invention, methods employing the above-described adhesive formulations are also provided, as are substantially void-free articles produced thereby.

Description

The The present invention relates to compositions which are useful for bonding of electronic devices with supports, as well as methods the desired To obtain connection, and substantially void-free objects, the thereby generated.

BACKGROUND OF THE INVENTION

The Microelectronics industry uses different substrates to keep it to attach microelectronic devices. Most of these Devices are made by using some type of glue attached to suitable substrates. Unfortunately, many are inclined the usual Substrates and / or devices used in the microelectronics industry to absorb moisture. If you like the elevated temperatures be exposed to the hardening Such adhesives may be required as a result of the release absorbed moisture and / or other volatile Substances coming from the device and / or the substrate at elevated temperatures can be released for the formation of cavities come in different amounts.

The Formation of cavities can greatly reduce the reliability of the resulting article to lead, because the glue joint between the device and the Substrate is interrupted. It would be therefore desirable To develop compositions and methods for their use which the assembly and the connection of the device with the Substrate enable, without a significant amount of voids in the finished article produce.

BRIEF DESCRIPTION OF THE INVENTION

According to the present Invention adhesive compositions have been developed, which the hardening of adhesively bonded structures (i.e. Include devices which glued to substrates by means of adhesive were) at dra cally reduced occurrence of cavitation while hardening enable. In many cases can by using the compositions of the invention, the cavitation be excluded.

According to one Another aspect of the present invention also provides methods, which use the adhesive formulations described above, as well as substantially void-free objects, which are generated thereby provided.

DETAILED DESCRIPTION THE INVENTION

According to the present The invention provides methods for reducing cavitation while hardening an adhesive preparation, used to connect a device to a substrate will be available with the device and / or substrate tending to at elevated Temperatures volatile Release substances. The methods of the invention include the Use of a catalyst which comprises curing the preparation in a Temperature of less than about 100 ° C initiated as a curing catalyst for such Adhesive formulations.

The intended for use in the practice of the present invention Adhesive preparations are u. a. Cyanate ester based preparations, Maleimide-based preparations, epoxy-based preparations, (meth) acrylate-based Preparations, vinyl ether-based preparations, vinyl ester-based Preparations, allyl ester-based preparations, diallylamide-based preparations, propargyl ether-based Preparations, preparations based on a polysiloxane backbone with one or more of the functional ones described above Groups at the end, preparations based on a pre-imidized polyimide backbone with a or more of the above-described functional groups at the end and the like, as well as mixtures of any two or several of them.

A wide variety of cyanate ester based formulations for the use in the practice of the present invention. numerous examples for such preparations have been described in the prior art. See, for example, the US patent No. 5,447,988, U.S. Patent No. 5,358,992, U.S. Patent No. 5,489,641, each of which is hereby incorporated by reference in its entirety.

A wide variety of maleimide-based formulations are suitable for use in the practice of the present invention. Numerous examples of such preparations are in the art been described. See, for example, US Application Serial No. 08 / 300,721, filed September 2, 1994, US Application Serial No. 08 / 460,495, filed June 2, 1995, US Application Serial No. 08 / 711,982, filed September 10, 1996 U.S. Patent No. 4,806,608 and U.S. Patent No. 4,581,461, each of which is incorporated herein by reference in its entirety.

A wide variety of through heat curable (i.e., thermosetting) Epoxy-based preparations are suitable for use in practice of the present invention. Numerous examples of such preparations have been described in the prior art. See for example U.S. Patent No. 5,158,780 and U.S. Patent No. 5,043,102, wherein each of which is hereby incorporated by reference in its entirety.

A wide variety of (meth) acrylate-based preparations for the use in the practice of the present invention. numerous examples for such preparations have been described in the prior art. See, for example, U.S. Patent No. 5,043,102, which is incorporated herein by reference in its entirety is.

A Wide variety of vinyl ether-based preparations is suitable for the Use in the practice of the present invention. numerous examples for such preparations have been described in the prior art. For example, see the US application number 08 / 460,495, filed June 2, 1995, incorporated herein by reference in its entirety is.

A Wide variety of vinyl ester based formulations is suitable for the Use in the practice of the present invention. numerous examples for such preparations have been described in the prior art. See, for example, the US patent No. 5,475,048, which is incorporated herein by reference in its entirety.

A wide variety of allyl ester-based preparations is suitable for the Use in the practice of the present invention. numerous examples for such preparations have been described in the prior art. See, for example, the US patent No. 5,475,048, which is incorporated herein by reference in its entirety.

A wide variety of diallylamide-based preparations for the use in the practice of the present invention. numerous examples for such preparations have been described in the prior art. See, for example, each of which is hereby incorporated by reference in its Entity included is.

A wide variety of propargyl ether based preparations for the use in the practice of the present invention. numerous examples for such preparations have been described in the prior art. See, for example, US Application No. 08 / 684,148 filed on July 19, 1996, hereby incorporated by reference in their entirety incorporated is.

Currently preferred adhesive preparations suitable for use in practice of the present invention comprise a mixture from maleimide and vinyl ether.

Possibly include those for use in the practice of the present invention adhesive preparations also provided at least one extender. For the Useful diluents herein are known in the art. a. electrical conductive and thermally conductive materials as well as non-conductive Materials that the resulting preparation insulating properties to lend.

Examples of electrically conductive diluents contemplated for use herein include silver, nickel, cobalt, copper, aluminum, metal-coated graphite fibers (using, for example, metals such as nickel, silver, copper, and the like as a metal coating), and the like and mixtures thereof. The currently preferred electrically conductive diluent contemplated for use herein is silver. In the mounting paste compositions of the present invention, both powder and flake forms of the extender may be used. The preferred thickness of the flakes is less than 2 microns with a dimension of about 20 to about 25 microns. The flakes contemplated for use herein have a surface area of about 0.15 to 5.0 m ² / g and a packing density of 0.4 to 5.5 g / cm ³ . The powder intended for use herein preferably has a diameter of about 0.5 to 15 microns.

Thermally conductive extenders, those intended for use in the practice of the present invention are u. a. Diamond, boron nitride, alumina, aluminum nitride, Silicon carbide, magnesium oxide and the like, and mixtures of any two or more of them.

catalysts those intended for use in the practice of the present invention are those which are curing the adhesive preparation at a desirable initiate low temperature and which is also the hardening of the Adhesive formulations promote with a sufficiently fast speed, so that this cure peak equally at a desirable low temperature, z. B. at a temperature of not higher than about 100 ° C, takes place. Currently preferred catalysts for use provided herein are those which cure the To promote adhesive formulations at such a rate that the cure peak maximum at a temperature of not higher as about 90 ° C occurs. Particularly preferred catalysts for use provided herein are those which cure the To promote adhesive formulations at such a rate that the cure peak maximum at a temperature of not higher as about 80 ° C occurs.

to Particularly preferred herein are catalysts which the hardening of adhesive formulations at such a speed promote, that this cure peak at a temperature of not higher as about 70 ° C occurs, wherein catalysts which curing the adhesive compositions promote at such a rate that the Aushärtungsspitzenmaximum at a temperature from no higher as about 60 ° C occurs in certain adhesive preparations especially are preferred.

to Use provided in the practice of the present invention Catalysts are u. a. radical catalysts, anionic curing catalysts, cationic curing catalysts, transition metal catalysts and the like, and combinations of any two or more from that.

exemplary free radical catalysts for use in the practice of Present invention are provided, u. a. peroxyesters Peroxycarbonates, hydroperoxides, alkyl peroxides, aryl peroxides and the like. Specific radical initiators intended for use herein are u. a. Cumene peroxyneodecanoate, cumene peroxyneoheptanoate, tert-amyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, tert-amyl peroxyneoheptanoate, tert-butyl peroxyneoheptanoate, a peroxydicarbonate, 2,4,4-trimethylpentyl-2-peroxyneodecanoate, Di (n-propyl) peroxydicarbonate, di (sec-butyl) peroxydicarbonate, di (4-tert-butylcyclohexyl) peroxydicarbonate, Di (2-ethylhexyl) peroxydicarbonate, dimyristyl peroxydicarbonate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, di ([3,5,5-trimethylhexanoyl] peroxide, decanoyl peroxide, Lauroyl peroxide, dilauroyl peroxide, diisononanoyl peroxide, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, 1-Amylperoxy-2-ethylhexanoate and the like, and combinations any two or more of them.

wobei:
R¹ ausgewählt ist aus der Gruppe, bestehend aus Alkyl-, Aryl- und Cyanoresten,
R² ausgewählt ist aus der Gruppe, bestehend aus Alkyl-, Aryl- und Cyanoresten, und
R³ ausgewählt ist aus der Gruppe, bestehend aus Alkyl, substituierten Alkyl-, Alkylaryl- und substituierten Alkyl arylresten.Exemplary anionic curing catalysts contemplated for use in the practice of the present invention include imidazoles, tertiary amines, and the like. The imidazoles contemplated for use herein are those having the general structure:

in which:
R ^{1 is} selected from the group consisting of alkyl, aryl and cyano radicals,
R ^{2 is} selected from the group consisting of alkyl, aryl and cyano radicals, and
R ^{3 is} selected from the group consisting of alkyl, substituted alkyl, alkylaryl and substituted alkylaryl radicals.

So As used herein, "alkyl" means straight or branched chain Alkyl radicals having from about 1 to 12 carbon atoms; "Substituted alkyl" means alkyl radicals which further include or carry a plurality of substituents, such as. As hydroxy, alkoxy (with a lower alkyl group), Mercapto (with a lower alkyl group), Aryl, heterocycle, halogen, trifluoromethyl, cyano, nitro, amino, Carboxyl, carbamate, sulfonyl, sulfonamide and the like.

So As used herein, "aryl" means aromatic radicals having 6 to 14 carbon atoms, and "substituted aryl" means aryl radicals further including or more than the above substituents carry.

So As used herein, "alkylaryl" means alkyl-substituted Aryl radicals, and "substituted Alkylaryl "means Alkylaryl radicals, which also have one or more substituents as mentioned above wear.

exemplary Imidazoles contemplated for use herein are, among others, a. 2-ethyl-4-methylimidazole, 1-methylimidazole, 2-methylimidazole, 2-undecylimidazole, 2-phenylimidazole and the like.

Tertiary amines, which are intended for use herein are u. a. hexadecyl, Dihexadecylmethylamine, octadecyldimethylamine, dioctadecylmethylamine, Dimethylbehenylamine, dimethylecosylamine, N, N, N'-trimethyl-N'-hexadecyl-1,2-diaminoethane, N, N, N'-trimethyl-N'-octadecyl-1,2-diaminoethane, N, N, N ' Trimethyl-N'-eicosyl-1,2-diaminoethane, N, N, N'-trimethyl-N'-phenyl-1,2-diaminoethane, N, N, N ', N'-tetramethyl-1,20- diamino (10,11-dioctyl) eicosane and the like, and mixtures of any two or more from that.

exemplary cationic curing catalysts, those intended for use in the practice of the present invention are u. a. Onium salts, iodonium salts, sulfonium salts and the like.

Exemplary transition metal catalysts, those intended for use in the practice of the present invention are u. a. Nickel, copper, cobalt and the like in the form a chelate, soap or the like.

in the general are in the range of about 0.005 to 10 wt .-% of at least one of the catalysts described above (based on the total weight the organic phase, d. H. without any extender), the range of about 0.01 to 5 wt% is currently preferred.

As The professionals will easily recognize a wide variety to devices according to the present invention Be glued invention. Examples of such devices are u. a. Silicon-based microelectronic devices, microelectronic Gallium arsenide based devices, microelectronic devices quartz-based, sapphire-based microelectronic devices, Indium phosphide based microelectronic devices, microelectronic Cadmium sulfide based devices, microelectronic devices lithium niobate-based and the like.

As well Those skilled in the art will readily recognize that many substrates according to the present invention Invention can be glued. examples for such substrates are circuit boards made from materials which tend to be at elevated temperatures volatile Release substances, eg. B. boards made of materials are, which tend to absorb water. Examples of such Boards are u. a. Bismaleimide triazine boards, epoxy boards, Circuit boards with a polyimide film on top, boards with a polycarbonate film on it, boards with a solder mask coating on it and the like.

According to another embodiment of the present invention, adhesive compositions are provided which are suitable for attaching a device to a substrate, wherein the device and / or the substrate tend to release volatiles at elevated temperatures, and wherein substantially no cavitation occurs during curing of the composition. The compositions according to the invention comprise:
Binders and
a catalyst which initiates the curing of the binder at a temperature of not higher than 100 ° C.

Binder, those intended for use in the practice of the present invention are u. a. Cyanate ester-based preparations, maleimide-based Preparations, epoxy-based preparations, (meth) acrylate-based Preparations, vinyl ether-based preparations, vinyl ester-based Preparations, allyl ester-based preparations, diallylamide-based preparations, Propargyl ether-based preparations, preparations based on a polysiloxane backbone having one or more of the above described functional groups at the end, preparations based on a pre-imidized polyimide backbone with one or more of the functional functionalities described above Groups at the end and the like, as well as mixtures of any two or more thereof as described hereinabove.

Similar are those for use in preparing the compositions of the invention provided catalysts such as described above, and such catalysts may be added in amounts, as described above, to the composition according to the invention.

So as used here means "im essentially void-free "one essentially continuous adhesive bonding between the device and the substrate, which are interconnected. Cavities are expressed as an interruption of this otherwise continuous bond and impair both the strength the resulting bond as well as the ability of such a bond, the influences from outside forces, like z. High moisture contents, high shear forces and the like.

The Invention will now be made by reference to the following non-limiting Examples in greater detail described.

example 1

For testing, a resin system was prepared using the following base formulation and various catalysts to determine the effect of catalyst choice on the occurrence of voids during curing. The base resin composition used comprises:
60 parts by weight of the bismaleimide 1,20-bismaleimido-10,11-dioctyleicosane,
30 parts by weight maleated polybutadiene R130 MA20 from Ricon Resins, Grand Junction, CO,
22 parts by weight of a branched C ₂₄ -monovinyl ether (ie the monovinyl ether of 2-decyltetradecanol),
4 parts by weight of a coupling reagent (e.g., 3 parts of A-186 (ie, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane) and part A-174 (ie, γ-methacryloxypropyltrimethoxysilane), both from OSi Specialties, Endicott, NY, available) and
1, 3 or 5 parts by weight of a catalyst.

The Catalysts used here are u. a. Perkadox 16S (di (4-tert-butylcyclohexyl) peroxydicarbonate, available Akzo Nobel), Trigonox 141 (2,5-dimethyl-2,5-di- (2-ethylhexanoylperoxy) hexane, available from Akzo Nobel) and Witco USP90MD (1,1-bis (tert-amylperoxy) cyclohexane available from Witco Chemical). Each of these catalysts has a 10 hour decomposition half life at 70 ° C or less and was in quantities of 1, 3 or 5 parts by weight added to the base preparation described above. Thus were nine pastes made for testing, each with 77% by weight silver flakes stretched. Differential scanning calorimetry (DSC) and a cavity test were done with each paste.

Of the Cavity test was carried out using a copper-plated BT (bismaleinamide triazine) resin a Taiyo PSR 4000 version AUS5 solder mask. The Substrate was 15-16 For hours, place in an 85/85 chamber to ensure that there is moisture absorption occurs. The nine pastes were attached to the substrate, with a 300 x 300 mil glass coverslip has been used. The pastes were held at 150 ° C for 60 seconds Hot plate device hardened.

The DSC was at a ramp rate of 10 ° C / minute carried out. The sample size used was about 20-30 mg. Analysis of the DSC shows the onset of cure, the cure peak maximum and the total energy released. The temperature at the beginning of the cure and the temperature at the cure tip maximum are in the table for each of the pastes indicated.

table

The The results presented above show that when sensitive to moisture Polymer no cavitation takes place under the platelets, as long as the temperatures of the onset of cure and the cure tip maximum both below 100 ° C lie.

Even though the invention in detail with reference to certain preferred embodiments It has been understood that modifications and variations of the meaning and scope of what is described and claimed are included.

Claims (26)

Method for reducing cavitation while hardening an adhesive preparation used to join a microelectronic Device is used with a substrate, wherein the device and / or the substrate tends to volatiles at elevated temperatures the process being used as a curing catalyst for the preparation involves the use of a catalyst which is capable of curing the Preparation initiated at a temperature of less than 100 ° C. Method according to claim 1, wherein the catalyst is curing promotes the preparation at a rate such that the cure peak maximum at a temperature of not more than about 100 ° C. Method according to claim 1, wherein the catalyst is a radical catalyst, an anionic curing catalyst, a cationic curing catalyst, a transition metal catalyst or a combination of two or more thereof. The method of claim 3, wherein the free-radical catalyst is selected from the group consisting of cumene peroxyneodecanoate, cumene peroxyneoheptanoate, tert-amyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, tert-amyl peroxyneoheptanoate, tert-butyl peroxyneoheptanoate, a peroxydicarbonate, 2,4,4-trimethylpentyl-2-peroxyneodecanoate, di (n-propyl) peroxydicarbonate, di- (sec-butyl) peroxydicarbonate, di (4-) tert-butylcyclohexyl) peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, dimyristyl peroxydicarbonate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, di- [3,5,5-trimethylhexanoyl] peroxide, decanoyl peroxide, lauroyl peroxide, dilauroyl peroxide, diisononanoyl peroxide, 2 , 5-dimethyl-2,5-di (2-ethylhexanoylperoxy) -hexane and 1-amylperoxy-2-ethylhexanoate. Method according to claim 1, wherein the catalyst is curing promotes the preparation at a rate such that the cure peak maximum at a temperature of not more than about 90 ° C. Method according to claim 1, wherein the catalyst is curing promotes the preparation at a rate such that the cure peak maximum at a temperature of not more than about 80 ° C. Method according to claim 1, wherein the catalyst is curing promotes the preparation at a rate such that the cure peak maximum at a temperature of not more than about 70 ° C. Method according to claim 1, wherein the catalyst is curing promotes the preparation at a rate such that the cure peak maximum at a temperature of not more than about 60 ° C. Method according to claim 1, wherein the adhesive composition is a cyanate ester-based preparation, a maleimide-based preparation, an epoxy-based preparation, a (meth) acrylate based formulation, a vinyl ether based Preparation, a vinyl ester-based preparation, an allyl ester-based Preparation, a diallylamide-based preparation, a propargyl ether-based preparation, Preparations based on a polysiloxane main chain with one or more of end functional groups described above, preparations based on a pre-imidized polyimide main chain with one or several of the functional groups described above at the end, or a mixture of two or more thereof. Method according to claim 9, wherein the adhesive composition is a mixture of maleimide and vinyl ethers. Method according to claim 9, wherein the adhesive composition further contains at least one extender. Method according to claim 1, wherein the device comprises a microelectronic device Silicon base, a gallium arsenide based microelectronic device, a quartz-based microelectronic device, a microelectronic device Sapphire-based device, a microelectronic device on an indium phosphide basis, a microelectronic device Cadmium sulfide base or a microelectronic device Lithium niobate is. Method according to claim 1, wherein the substrate is a circuit board, the volatiles on exposure to increased Temperatures released. Method according to claim 13, wherein the substrate comprises a bismaleimide triazine board, an epoxy board, a board with a polyimide film on it, a board with a Polycarbonate film on top or a board with a solder mask coating on it is. Adhesive composition, suitable for fastening a microelectronic device on a substrate, wherein the Device and / or the substrate tend to be at elevated temperatures volatile substances release, and wherein substantially no cavitation at hardening the composition occurs, which contains: a binder, and one Catalyst curing of the binder at a temperature of not more than 100 ° C initiated. The composition of claim 15, wherein the catalyst promotes curing of the composition at a rate such that the cure peak maximum is at a temperature of zero when about 100 ° C occurs. A composition according to claim 15, wherein the catalyst a radical catalyst, an anionic curing catalyst, a cationic one curing catalyst, a transition metal catalyst, or a combination of two or more thereof. A composition according to claim 17, wherein the radical Catalyst selected is selected from the group consisting of cumene peroxyneodecanoate, cumene peroxyneoheptanoate, tert-amyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, tert-amyl peroxyneoheptanoate, tert-butyl peroxyneoheptanoate, a peroxydicarbonate, 2,4,4-trimethylpentyl-2-peroxyneodecanoate, di (n-propyl) peroxydicarbonate, Di (sec-butyl) peroxydicarbonate, di (4-tert-butylcyclohexyl) peroxydicarbonate, Di (2-ethylhexyl) peroxydicarbonate, dimyristyl peroxydicarbonate, tert-Amyl peroxypivalate, tert-butyl peroxypivalate, di- [3,5,5-trimethylhexanoyl] peroxide, Decanoyl peroxide, lauroyl peroxide, dilauroyl peroxide, diisononanoyl peroxide, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) -hexane and 1-amylperoxy-2-ethylhexanoate. A composition according to claim 15, wherein the catalyst the hardening promotes the composition at a rate such that the cure peak maximum at a temperature of not more than about 90 ° C. A composition according to claim 15, wherein the catalyst the hardening promotes the composition at a rate such that the cure peak maximum at a temperature of not more than about 80 ° C. A composition according to claim 15, wherein the catalyst the hardening promotes the composition at a rate such that the cure peak maximum at a temperature of not more than about 70 ° C. A composition according to claim 15, wherein the catalyst the hardening promotes the composition at a rate such that the cure peak maximum at a temperature of not more than about 60 ° C. A composition according to claim 15, wherein the binder a cyanate ester based formulation, a maleimide-based Preparation, an epoxy-based preparation, a (meth) acrylate-based Preparation, a vinyl ether-based preparation, a vinyl ester-based Preparation, an allyl ester-based preparation, a diallylamide-based Preparation, a propargyl ether-based preparation, preparations based on a polysiloxane backbone with one or more of the functional ones described above Groups at the end, preparations based on a pre-imidized polyimide backbone with one or more of the functional ones described above Groups at the end, or a mixture of two or more of them is. A composition according to claim 15, wherein the binder contains a mixture of maleimide and vinyl ether. A composition according to claim 15, wherein the composition further contains at least one extender. Component that is essentially void-free and after the method according to claim 1 is made.